The exception was the -845T>C IL8 polymorphism in nonsmokers: the -845C allele and -845TC genotype were associated with susceptibility to chronic periodontitis (-845C allele: 3.6% vs 0.4%; OR = 10.4; -845TC genotype: 7.3% vs 0.7%; OR = 10.1). This evidence concerns the gene CXCL8 and chronic periodontitis.